Method and apparatus for forming pulp articles



ARTICLES W. P. LASS I June 11, 1940.

METHOD AND'APPARATUS FOR FORMING PULP Filed July 27, 1936 5 Sheets-Sheet 1 R. Y3. N m E v N N w m a g a W 2 5 MM .0 T w 6 N o /v I .Q 8 Y N.\\1 m B 0 mm we 0 |1." 6 mm 00 of... m N N. o o mm \N. 4 Mb. 0 o o t w hm o n R Q Q H. z G MW S Q v hm Q 3 o v w mm mu 6 lax. hm. #u ow i w ON June 11, 1940. w. P. LASS 2,204,276

METHOD AND APPARATUS FOR FORMING PULP ARTICLES Filed July 27, 1936 5 Sheets-Sheet 2 224. dim 7 10M ATTORNEY ARTICLES June 11, 1940. w. P. LASS awmon AND APPARATUS FOR FORMING PULP Filed July 27, 1936 5 Sheets-Sheet 5 A TTORNEY.

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W. P. LASS June 11, 1940.

' METHOD AND APPARATUS FOR FORMING PULP ARTICLES Filed July 27, 1936 5 Sheets-Sheet 4 INVENTOR.

4% @W" ATTORNEY.

June 11, 1940.

METHOD AND W. P. LASS APPARATUS FOR FORMING PULP ARTICLES Filed July 27, 1936 III '- ss E 5 Sheets-$heet 5 INVENTO ATTORNEY.

Patented June 11, 1940 UNITED STATES PATENT OFFICE METHOD AND APPARATUS FOR FORMING PULP ARTICLES 10 Claims.

This invention relates to a method and apparatus for forming articles from pulp, and particularly to improvements in machines of the kind disclosed in Patent No. 1,697,244, issued January 1, 1929, to E. P. Kennedy.

It is common practice, in forming articles, such as plates, baskets, and the like from pulp, to employ molds of screen or perforate sheet metal, to dip these molds into the fluid mass of pulp and water, and to pump air from the interior of the molds to effect a vacuous condition, retaining the pulp against the surface of the mold and drawing a part of the water from the pulp through the molds.

The term pulp as employed in the following specification is to be understood broadly as including any pulp-like or fibrous substance whether or not it be mixed with agents for coloring, waterproofing, insulating or otherwise conditioning the articles to be made.

It is an object of the present invention to provide a generally improved method and apparatus for forming and drying pulp articles; to provide for natural drainage of moisture from the articles during the entire period of drying; to provide means for regulating and controlling the vacuum on different portions of the article and at different stages of its manufacture; and to provide a machine having various features tending to expedite, simplify and reduce the cost of manufacture of molded pulp articles.

One form of the invention is illustrated in the accompanying drawings, and further of the objects and advantages thereof will be made apparent in the following specification, wherein detailed reference is made to the drawings.

In the drawings:

Fig. 1 is a fragmentary plan view of a machine embodying the improvements of the present invention.

Fig. 2 is a central, vertical section of the machine illustrated in Fig, 1.

Fig. 3 is a view of a portion ofthe mechanism illustrated in Fig. 2 and showing the mold assembly in the lowered position occupied while pass-' ingthrough a pulp tank.

Fig. 4 isa view of the portion of the machine illustrated in Fig. 3 and showing the position of the mold assembly occupied during its passage over a conveyer belt which receives the completed articles as they are discharged therefrom.

Fig. 5 is an enlarged view of the mechanism which imparts the movements to the mold assembly illustrated in Figs. 3 and 4.

Fig. 6 is a plan view of that mechanism illustrated in Fig. 5.

Fig. 7 is a sectional view, taken on the line VIIVII of Fig. 5.

Fig. 8 is an enlarged vertical sectional view of 6 a mold assembly.

Fig. 9 is a sectional view, taken on the line IX-IX of Fig. 8.

Fig. 10 is a sectional view, taken on the line X-X of Fi 8.

Fig. 11 is a central, vertical, sectional view on an enlarged scale of the rotor and manifold which carry the mold assemblies.

Fig. 12 is a sectional view, taken on the line XII-XII of Fi 11.

Referring first to Figs. 1 and 2 of the drawings, the machine is' illustrated as comprising a horizontally disposed, rotary manifold, generally indicated at H), which carries radial tubular arms II in a generally horizontal plane. Each horizontal arm ll supports a mold assembly, generally indicated at 12, at its outer end comprising a plurality of articulated complementary mold sections.

As illustrated in Fig. 2, a motor l3 may drive a set of reduction gearing II to rotate a pulley I5 at a reduced speed. A belt l6, driven by the pulley l5, embraces a large pulley H which is supported on legs I8 extending downwardly from the arms II. The lower ends of the legs I! are provided with casters 19 which travel on an annular track 20 to brace the arms II and support the weight of the mold assemblies at their outer ends. The direction of the rotation imparted to the machine by the motor and. drive connections described is counter-clockwise, as vieweddn Fig. 1, so that the mold-assemblies pass in succession over and into a pulp tank 22, shown in Figs. 1 and 3. The molds then pass through the major arc of their circular path, during which time they undergo a drying process and then pass over a conveyer 23, illustrated in Figs. 1 and 4, upon which conveyer the molded and dried. articles are automatically deposited by means presently to be described.

A typical mold assembly is shown in Figs. 8, 9 and 10. The mold illustrated in the'drawings is for a milk bottle, out the principles embodied in this mold are adaptable to forming hollow articles of various contours. The mold shown comprises four hollow mold sections with imperforate outer walls and perforate or screen-like inner walls shaped to form the exterior of the article to be molded. A top section 24 forms the bottom of the bottle; a pair of side sections 25 and 26 form side walls of the bottle; and a bottom section 21 forms the top or open end of the hollow article. The side sections 25 and 26 are preferably guided together to assure accurate registry by tabs or ears 28, two or more of which may be secured to each section to overlap the other section as they are brought together. Each of the hollow mold sections is provided with a tubular outlet 29 formed adjacent to its bottom wall and preferably inclined to cause drainage of moisture away from the perforate mold wall.

The bottom mold section 21 carries a pulp inlet consisting of a tube 30 extending through the section to permit entry of pulp to the inside of the mold when the mold sections have been brought together and dipped into a tank of fluid pulp.

During the operation of the machine, air is drawn through the mold, entering through the pulp inlet, passing through the perforate mold walls and out of the hollow mold sections through the outlets 29. Upon immersion of the pulp inlets 30 into fluid pulp, the pulp is drawn into the mold, and spreads over the inner walls there of. As the perforate walls arerendered imperforate by their covering of pulp and the suction is continued, a partial vacuum is eiTected in the hollow mold sections, causing the pulp to adhere in an even coating and assisting in the removal of moisture from the pulp to form a finished dried product.

The manner of supporting the mold sections articulately for opening and closing and for connecting them with a common air blower or suction mechanism is illustrated in Figs. 1 to '7, inclusive. To the outer end of each of the radially extending arms ll there is attached, by means of a union 3| or other suitable connection, a hollow T-shaped fitting 32. The transversely extending portion of the T-shaped fitting 32, as illustrated in Fig. 7, receives rotatably a tube 33 which is ported, as at 34, for communication with the interior of the hollow radial arm A vertical fitting 35, threaded to one end of the tube 33, supports a rigid arm 36 which carries at its outer end the side mold section 25. A vertical fitting 31, on the opposite end of the tube 33, carries within it a rotatable sleeve 38 which is ported, as at 39, for registry with the interior of the tube 33. The upper end of'the sleeve 38 carries an elbow 40 which supports an arm 4|, the outer end of which arm carries the side mold section 26 which, due to the rotatable sleeve 38,

may be swung outwardly in a horizontal plane to be separated from the ether mold sections.

In order to support the top and bottom mold sections to swing vertically to and away from the mold assembly. the fitting35 isce Fig. '1) is tapped to carry a shaft 42, which supports a pair of rotatable sleeves and 46. The sleeve 45 carries the inner end of a tubular arm 41 which .is welded to it. The outer end of the arm 41 supports the upper mold section 24. The sleeve 46 similarly carries the lower mold section 21 by means of an arm 49. The extreme inner ends of the tubular arms 41 and 49 are shown at 50 and 5|, respectively, in Fig. 8, and are connected ,with flexible hoses 52 and 53 leading inwardly for communication with the common source of vacuum through a manifold presently to be described in detail.

The entire assembly, illustrated in Figs. 5 and 6, rocks about the central, longitudinal axis of the fitting 32, so that the mold assembly may be raised and lowered in the manner illustrated is providedwith a turnbuckle, as shown, so that in Figs. 3 and 4. Brace members 54 and 55 extend rearwardly from the vertical fittings 35 and 31 and are connected at their innermost ends by means of a rod 56 (see Figs. 2, 3 and 4) with a lever 51 which is pivoted, as at 58, to the leg 5 l8. The outer end of each lever 51 carries a roller 59 which travels in a track 6|] as the mold assemblies move in their circular path. The track 60 is disposed normally to maintain the mold assembly in the positionv illustrated in Fig. 2, which position is such that all of the tubes leading from the mold sections inwardly toward the rotary manifold, including the main tubular arm H and the flexible tubes 52 and 53, are

chine at a slight angle to provide for the natural drainage of any moisture that is drawn from the molds or any precipitated moisture that might form in the tube during the drying operation.

At the point where the molds pa" over the pulp tank the track 60 is curved downwardly or dipped so that, as illustrated in Fig. 3, the lever 51 is rocked to impart a downward swinging movement to the mold assembly through the connecting rod 56 and cause the molds to be immersed in the pulp carried in the tank 22. The track then rises to the position of Fig. 2 to retain the molds in their generally horizontal position throughout the major portion of the drying operation and until the articles are ready to be,

entire mold assembly slightly upwardly and ef- 35 fecting separation of the mold sections at the time that the mold passes over the conveyer 23. The separation of the mold sections is efiected by bell-cranks carried by the mold assembly and having rollers engageable with a plate 6|, one of which plates is carried on each of the radial arms II.

The construction of this mechanism is also illustrated in Figs. 5 and 6, wherein a common pivot pin 62 is shown as supporting a bell-crank 63 having a roller 64 on one end and having its opposite end connected by a link 65 with a crank arm 66 rigidly secured to the top of the elbow 40, so that upon upward swinging of the assembly the roller 64 contacts the plate 6| to swing the bell-crank forwardly and swing the crank arm 66 forwardly to move the arm 4|, carrying the 'side mold section 25 outwardly and away from 'mold. Likewise a bell-crank 10 with a-roller 64 contacting the plate 6| operates a rod 1| to swing a crank arm 12 which is connected with the tube 46 and thus to lower the bottom section 21 of the mold assembly. r

- As each of the connecting rods 65, 68 and 1| 65 the length thereof may be adjusted, the exact timing of the contacting of the rollers 64 with the plate 6| may be varied to cause the several mold sections to swingtoward and away from their assembled position in any desired order. 70

Springs 15, as illustrated in Fig. 5, may connect the outer ends of the cranks 66, 69 and 12 with the common pivot pin 62.0r a point adjacent to 'said pin, normally to, urge the several mold sections toward their closed or assembled position.

The construction of the horizontal rotor and manifold H1 is illustrated in Figs. 2, 11 and 12'. A vertically extending hollow stand 80 supports a stationary bearing at its upper end. This bearing comprises a bottom flange 8| and a top flange 82, the latter of which is supported by upper ends of vertically extending posts 83 and secured thereto by cap screws 84. A rotatable collar 85 is carried between the flanges 8| and 82 and an airtight seal is effected by gaskets 86 which 'may be embedded in grooves formed in the flanges. This construction of the rotor bearing presents a decided advantage over other bearings that have been used for this purpose as there is a partial vacuum within the interior of the manifold tending to draw the flanges 8| and 82 toward each other and frictionally resist the rotational movement of the collar 85. In the present construction the vertical posts 83 positively prevent any variation in the spacing between the flanges 8| and 82 and thus permit free rotation of the rotary collar, regardless of variations of pressure within the manifold.

A suction blower of any suitable type may be connected with the interior of the manifold through a pipe 88, illustrated in Fig. 2, to draw air through the manifold and through all of the molds which are connected with the interior of the manifold through the radial arms I and the tubes 52 and 53, all of which join the rotary collar 85.

It is desirable to vary the intensity of the suction through the molds at different times during their cycle of operation as well as to vary the suction in the different mold sections at the time that the pulp is being deposited in the mold. For ideal operation the suction in all of the mold sections should be comparatively light as the mold dips into the liquid pulp and should increase gradually as the mold emerges and undergoes its initial drying. It is also desirable to vary the suction on different mold sections to effect a greater or less deposit of pulp on certain surfaces and thus to increase the strength of the article at desired points. When the molded article is fully dried and ready to be discharged from the mold, the suction should be cut off altogether, and as the molds open a blast of air moving in a direction opposite to the suction is desirable to assist in removing the articles from the moldand to clean the perforate mold walls of any small particles which may adhere to them. This regulation and variation of air pressure through the molds is effected through valve plates 90, 9| and 92, as shown in Figs. 11 and 12, which close the openings to the tubes 52 and 53 during a part of their cycle and which are perforated, as illustrated 'at 94 in Fig. 12, to cause a gradual increase in intensity of the suction pass ing through the molds at the proper time. The plates 90, 9| and 92 are carried by threaded studs, such as indicated at 95, which are adjustably carried by nuts 96 to the inner surfaces of three of the vertical posts 83.

As viewed in Fig. 12, the movement of the rotary collar 85 is in a counter-clockwise direction and the valve plates 90, 8| and 92 are so positioned that the openings for the tubes 52 and 53 which lead to the molds are closed just prior to the movement of each mold assembly over the conveyer belt 23. As the mold passes over the belt its sections are separated in the manner illustrated in Fig. 4 and at the same instant the inner end of the tubular arm registers with a pipe 99 which carries air under pressure from any suitable source. This causes a momentary blast of air to be delivered through the side mold sections to insure the removal of the completed article from the mold and to clean any debris from the perforate mold walls. Pipes similar to that shown at 99 may also lead air under pressure to the valve plates 9| and 92, so that a blast of air will also be blown through the top and bottom mold sections, if desired.

As the molds close, the inner ends of the tube pass an imperforate part in the valve plates 90, 9| and 92 and just as the molds are dipped into the pulp tank, as illustrated in Fig. 3, the tubes register with the ports 94 in the valve plates which permit the suction to become effective in the molds. The ports 94 gradually increase in size so that the suction in each mold gradually increases in intensity as the mold passes through the pulp tank and emerges therefrom. The size of the ports 94 may be varied for the different mold sections so that more or less of the liquid pulp may be caused to be deposited upon any desired portion of the article being molded.

Owing to the manner of construction of the machine described above, there is a natural drainage maintained at all times during the drying operation between the pulp article and the central rotary manifold. This prevents any possibility of moisture that has been drawn from the pulp or condensation formed in the tubes returning to contact the dried or partially dried article. Furthermore, this feature obviates the necessity of intense heat to dry the articles and the usual ovens, and the like, may be done away with entirely.

A small heater in the form of a Bunsen flame may be used to advantage by simply placing it in a position where heat radiated from it may enter the pulp inlets of the molds asthey pass it during their drying cycle. 3

Various types of molds are used for forming articles of different shapes, and the machine of the present invention may be used with ordinary open molds or transfer molds as well as with the split mold shown for forming hollow ware. Likewise it is apparent from the foregoing description that the method and apparatus disclosed herein are readily adaptable to separating liquids and solids of various kinds as well as drying the solids whether or not it is desired to produce articles of any particular shape from the solids.

Though certain features of the invention are more or less specifically described, it should be understood that various changes may be resorted to in the arrangement and construction of its several parts within the scope of the appended claims.

What I claim is:

1. The method of molding pulp articles which comprises introducing pulp in fluid suspension to a perforate mold surface, then subjecting the opposite surface of the mold to suction to effect deposit of the pulp on the mold surface, gradually increasing the intensity of the suction to a maximum, and maintaining said maximum suction until the article is ready to be discharged from the mold.

2. The method of molding pulp articles which comprises passing a perforate mold through pulp in a fluent state, subjecting the mold to gradually increasing suction as it passes through and emerges from the pulp, and then maintaining suction on the mold until the moisture has been removed, from the molded article.

3. An apparatus for molding pulp articles which comprises a mold, a hollow arm supporting the mold, means moving said arm to pass the mold through a supply of pulp in liquid form, and means for supporting the arm at an angle to cause moisture to drain away from the mold and through the arm constantly until the article is dry.

4. An apparatus for molding pulp articles which comprises a rotor, radial hollow arms carried by the rotor to be revolved thereby in a horizontal plane, molds carried at the outer ends of said arms, means for dipping said molds into a pulp vat during a portion of their rotary cycle, and means for maintaining the molds at an elevation to insure drainage of moisture from the molds through said arms throughout the remainder of said cycle.

5. In an apparatus for molding pulp articles which comprises separable mold sections connected with a source of vacuum through individual tubes communicating with a rotating manifold, means for varying the intensity of the vacuum in the different mold sections comprising a stationary plate within the rotary manifold covering the ends of said tubes and provided with perforations of progressively varying sizes registering with the ends of the tubes as the manifold rotates.

6. A mold for forming hollow pulp articles or the like comprising a plurality of complementary mold sections, each section being hollow, separate conduits connecting each section with a source of vacuum, and a perforate wall portion in each section combining with the perforate wall of the other sections to form a mold for the exterior surface of the article to be made.

7. In an apparatus for forming pulp articles, the combination of a perforate mold, conduits communicating with the mold, means for introducing pulp to the mold surfaces, means for effecting a vacuum within the mold through said conduits, and maintaining the conduits and mold in a position to effect complete drainage away from the mold and through the conduits during drying of the pulp on the mold.

8. In an apparatus for forming pulp articles, the combination of a perforate mold, conduits communicating with the mold, means for introducing pulp to the mold surfaces, means for effecting a vacuum within the mold through said conduits, and maintaining the conduits and mold in a position to effect complete drainage away from the mold and through the conduits during drying of the pulp on the mold, and means for directing air through said conduits to discharge"? the dried pulp articles from the mold.

9. In an apparatus for forming pulp articles, the combination of a perforate mold formed of separable sections, tubular arms supporting said sections for movement to and away from each other, means for introducing pulp to the mold, means for drying the pulp on the mold, means for directing a blast of air through said tubular arms to effect removal of the dried pulp articles from the mold sections, and means for supporting the mold sections and tubular arms in a position to eflect complete drainage of all moisture away from the mold and through the arms during the drying of the pulp, whereby said blast of air will be free from moisture.

10. In an apparatus for forming pulp articles. the combination of a perforate mold formed of separable sections, conduits communicating one with each of said sections, means for introducing pulp to the mold. means for drying the pulp on the mold, means for directing a blast of air through said conduits to effect removal of the dried pulp articles from the mold sections, and means for supporting the mold sections and said conduits in a position to effect complete drainage of all moisture away from the mold and through the conduits during the drying of the pulp, whereby said blast of air will be free from moisture.

WILLIAM P. 'LASS. 

